The present invention relates to a liquid crystal display device, and more particularly to the reflector-contained liquid crystal display device having an effective function for reflective color display and the manufacture of the liquid crystal display device.
As a conventional reflective type color liquid crystal display device, some methods for manufacturing the device have been proposed as disclosed in JP-A-3-223715, JP-A-5-80327, and JP-A-4-243225. In those methods, a rugged (convexo-concave) surface is formed under a reflecting film. Those methods are used for simply manufacturing the liquid crystal display device (often called LCD) having the diffused reflecting film built therein.
The structures formed by those methods are (1) a structure composed of an aluminum thin film formed on a ground glass surface, (2) a two-layered structure composed of a reflective electrode and a thin film layer having a different thermal expansion coefficient from the reflective electrode, and (3) a structure-composed of a reflecting film formed on a surface with lots of fine convex portions formed by plastics. Those structures each use both the reflector and the electrode.
In the foregoing prior art (1), the fine convex and concave portions are formed on a glass substrate by means of the sandblast technique, for example. In the foregoing prior art (2), the fine convex and concave portions are formed on the reflecting film surface by means of stress caused by the difference of a thermal expansion coefficient between the reflecting film and the plastics formed under the reflecting film.
Further, those reflecting films are patterned and served as both the reflector and the electrode.
However, those methods have problems of (1) inferior reproducibility of the fine rugged pattern, (2) difficulty in patterning the reflecting film, (3) difficulty in forming a color filter on the reflecting film, and so forth.
Further, the foregoing structure (3) is formed with a photo polymer by means of the photo-lithography technique. It means that the manufacturing process is complicated and has lots of steps. The manufacturing process is therefore very costly. Moreover, since the reflector is also served as an electrode, the composition where a color filter is formed on the reflector disadvantageously results in lowering a voltage to be applied to the liquid crystal.
The foregoing structures (2) and (3) include a plastics layer under an electrode terminal. In the connecting process of heating and pressing a tape carrier package (called a TCP through the rest of this description) having a liquid crystal driver IC mounted thereon through a conductive layer, therefore, those structures are likely to bring about a bad connection and film strip in the electrode terminal. Moreover, those structures have difficulty in re-connection as well.
It is an object of the present invention to provide a diffused reflector from which the foregoing disadvantages are removed, a liquid crystal display device constructed to use the diffused reflector, and a manufacture of the liquid crystal display device.
In order to achieve this object, the present invention is composed as follows:
[1] A diffused reflector composed of a substrate, a rugged thin film formed on the substrate, and a reflecting layer formed on the rugged thin film, the thin film layer being integrated with the reflecting layer in advance.
[2] The diffused reflector of [1] having an adhesive layer for bonding the thin film and the reflecting layer.
[3] A diffused reflector composed of a substrate and a diffused reflecting layer transcribed onto and bonded with the substrate by a transcription film.
[4] A diffused reflector composed of a substrate, a rugged thin film formed on the substrate, a reflecting layer formed on the rugged thin film, and a flatting layer formed on the reflecting layer, the thin film layer being integrated with the reflecting layer in advance and the thin film layer being bonded with the substrate by an adhesive layer.
[5] The diffused reflector of [4] having the thin film served as the adhesive layer.
[6] A liquid crystal display device composed of a pair of substrates, a liquid crystal layer laid between the pair of substrates, an adhesive layer formed on one of the pair of substrates, a rugged thin film formed on this adhesive layer, a reflecting layer formed on the rugged thin film, and a flatting layer formed on this reflecting layer, and an electrode structure for generating an electric field in the liquid crystal located between the flatting layer and the other one of the pair of substrates.
[7] A liquid crystal display device composed of one electrode substrate a having a glass substrate, a plastics layer with convex portions or convex and concave portions randomly formed on the glass substrate, a lamination of a reflector, an insulating and flatting layer, a transparent electrode, and alignment layer formed on the plastics layer and the other electrode substrate b having a transparent electrode and alignment layer laminated on the glass substrate, the electrode substrates a and b being located so that the alignment layer of them are opposed to each other and having a liquid crystal layer laid there between.
[8] The liquid crystal display device of [7] having a shading layer and a color filter formed on the insulating and flatting layer and the liquid crystal having its thickness regulated by plural plastics columns formed on the shading layer.
[9] A method for manufacturing the liquid crystal display device including the steps of locating one electrode electrode a formed by the substeps of forming a thin plastics layer on the glass substrate and forming fine convex portions or convex and concave portions on the plastics layer by heating and pressing the surface of the plastics layer with a pattern having lots of fine convex portions or convex and concave portions formed thereon, forming the reflecting film on the plastics layer and the insulating and flatting layer on the reflecting film, forming the shading layer and the color filter on the insulating and flatting layer, forming the flatting layer on the color filter, forming the transparent electrode on the flatting layer, forming the alignment layer of the liquid crystal on the transparent electrode, and the other electrode substrate b formed by the substeps of forming the transparent electrode on the glass substrate and forming the alignment layer.of the liquid crystal on the transparent electrode in a manner to oppose the alignment layer of the electrode substrates a and b to each other; filling liquid crystal between both of the electrode substrates; and sealing the liquid crystal therebetween.
[10] The manufacturing method for the liquid crystal display of [9] including the steps of forming lots of fine convex portions or convex and concave portions on the surface of the glass substrate; heating and pressing a transcription film having a photo or thermoset plastics layer laminated on a polymer base film with lots of fine convex portions or convex and concave portions formed at random; and stripping the polymer base film off the glass substrate.
[11] The manufacturing method for the liquid crystal display device of [9] or [10] further including the step of forming plural plastics columnar portions for regulating the thickness of the liquid crystal layer on the shading layer formed on the flatting layer.